Re: AW: Deconstructing OAM&P
Heiles,
You are correct. If 10GbE does not get implemented with the ability to leverage
the SONET/SDH operations and maintenance functions, then it will have to
implemented with something like a digital wrapper. A digital wrapper will
increase the signaling rate well beyond the native signaling rate that might be
implemented using either a scramble encode or a block encode. It will also
require that all new facilities be installed to handle 10GbE in Metro and Long
Haul services. Except for server farms and internal building aggregations
systems, this will cause a major increase to the cost of 10GbE interfaces and
implementation. It is something that I would very much like to see avoided.
Thank you,
Roy Bynum
MCI WorldCom
Heiles Jargon wrote:
> I am following the OAM&P discussion only for a short time and have a
> question for clarification.
>
> Currently two data rates for 10GbE are under discussion 10 Gbit/s and
> 9.58464 Gbit/s. As far as I understand, 9.58464 Gbit/s is proposed as it
> would allow mapping of 10 GbE into a SONET STS-192c SPE. In this case SONET
> could provide all the required OAM&P functions via its section, line and
> path overhead. The STS-192c SPE would be the end-to-end path discussed
> below.
> So I assume that the OAM&P discussion is related to the case the 10 GbE is
> not transported via SONET or similary transport techniques which provide the
> same OAM&P functionality (e.g. Digital Wrapper for the OTN).
> Is this assumption correct?
>
> Juergen Heiles
> Siemens AG
>
> > -----Ursprüngliche Nachricht-----
> > Von: Roy Bynum [SMTP:rabynum@xxxxxxxxxxx]
> > Gesendet am: Dienstag, 24. August 1999 07:58
> > An: rtaborek@xxxxxxxxxxxxxxxx
> > Cc: HSSG
> > Betreff: Re: Deconstructing OAM&P
> >
> >
> > Rich,
> >
> > I believe that we are agreeing that the only level of operations and
> > performance information
> > that is needed to be leveraged from the SONET/SDH system is the "Path".
> > You do not want to use
> > inband traffic bandwidth to send and receive physical layer operations and
> > maintenance
> > information. All of these things would not be as available without
> > leveraging the SONET/SDH
> > technology. Otherwise a lot of time will be spent developing new
> > technology might delay the
> > deployment of 10GbE and the additional development money will have to
> > recovered in a higher
> > cost interface. Since 10GbE is going to be full duplex, the fiber or
> > wavelength that will
> > transmitting, will not be same as the one that is receiving. There will be
> > two separate "links"
> > between any two interface ports.
> >
> > Thank you,
> > Roy Bynum
> > MCI WorldCom
> >
> > Rich Taborek wrote:
> >
> > > Roy Bynum wrote:
> > >
> > > > Rich,
> > > >
> > > > You are correct. A full duplex Ethernet link is equivalent to the
> > "Path" of a
> > > > SONET/SDH system. I believe that the new term that is being used in
> > the OIF is
> > > > "Trail".
> > > >
> > > > The "Line" definition within SONET/SDH are equivalent to the WAN
> > service link. This
> > > > would apply to situations where 10GbE would be put on active DWDM
> > systems or commercial
> > > > SONET/SDH services. The active "Line" information processing would be
> > done on the
> > > > active DWDM or the SONET/SDH systems, not the 10GbE port or switch.
> > The "Section"
> > > > function of SONET/SDH deals with physical fiber connections between
> > DWDM or SONET/SDH
> > > > Line Terminating Equipment or regenerators. Again, this would not be
> > part of the 10GbE
> > > > port or switch processing.
> > >
> > > This sounds appropriate. Is a fair comparison that a "Line" is
> > equivalent to a SONET/SDH
> > > transport which could encapsulate the payload of 10 Gbps Ethernet
> > packets? Is the equipment
> > > that commonly converts from one to the other commonly referred to as a
> > bridge or router? If
> > > it is, then this discussion is not relevant to the objectives of the
> > HSSG. The HSSG is
> > > focused on developing 10 Gbps Ethernet optical links to meet distance
> > requirements of up to
> > > 40 km.
> > >
> > > > Within the SONET/SDH path OAM functionality are several items that
> > would be useful.
> > > > There is a path origination identification that is equivalent to the
> > port MAC address
> > > > of an Ethernet port. This allows service providers to identify the
> > customer link
> > > > without looking at any of the data. It will also allow MAC to MAC
> > link identification
> > > > without impacting any of the active traffic. There is a bit
> > interleave parity function
> > > > that can be used to detect bit errors that also does not impact active
> > traffic. There
> > > > is a status indicator that can send some status and link received
> > error performance
> > > > information back to the far end port, again without impacting the
> > active traffic.
> > > > There are other items that might also be used. I will be going over
> > these at the Kent
> > > > meeting.
> > >
> > > In native Ethernet, there is no need to burden the Physical layer with
> > overhead
> > > specifically allocated to configuration or link maintenance and its
> > corresponding
> > > management. In general, packet-based LANs and SAN, including Ethernet,
> > meet configuration,
> > > link maintenance and general management requirements by architecting
> > measurement facilities
> > > at the Physical layer and Transport facilities at the MAC layer and
> > above. The reasoning
> > > being that since optical links typically operate at link BER rates much
> > lower than 10^-12,
> > > and that configuration and other management requests are very
> > infrequent. Therefore, a more
> > > efficient use of link bandwidth is to send management packets on an
> > as-needed rather than
> > > synchronous basis. This to me "impacts the active traffic" much less
> > than does a
> > > synchronous management transport alternative.
> > >
> > > Please also note the protocol danger of reporting management (e.g.
> > error) information using
> > > the same link which recognized the error, and of using the same and
> > loop/ring protocol to
> > > do so. Much confusion can result, akin to playing the game of
> > "telephone", with a group of
> > > folks arranged in a circle whispering in each others ear. The original
> > transmitter of the
> > > message will typically and eventually receive a corrupted copy of the
> > original message.
> > > This problem is solved by employing switched architectures and higher
> > level-based protocol
> > > transports.
> > >